1 | /* |
2 | * Copyright (C) 2010 Apple Inc. All rights reserved. |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions |
6 | * are met: |
7 | * 1. Redistributions of source code must retain the above copyright |
8 | * notice, this list of conditions and the following disclaimer. |
9 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
14 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
15 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
17 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
18 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
19 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
20 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
21 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
22 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
23 | * THE POSSIBILITY OF SUCH DAMAGE. |
24 | */ |
25 | |
26 | #ifndef PageBlock_h |
27 | #define PageBlock_h |
28 | |
29 | namespace WTF { |
30 | |
31 | // avoid false positive detection by apple |
32 | // by putting the function inside an inline namespace |
33 | // to obtain different name mangling |
34 | inline namespace hidden { |
35 | WTF_EXPORT_PRIVATE size_t pageSize(); |
36 | WTF_EXPORT_PRIVATE size_t pageMask(); |
37 | } |
38 | inline bool isPageAligned(void* address) { return !(reinterpret_cast<intptr_t>(address) & (pageSize() - 1)); } |
39 | inline bool isPageAligned(size_t size) { return !(size & (pageSize() - 1)); } |
40 | inline bool isPowerOfTwo(size_t size) { return !(size & (size - 1)); } |
41 | |
42 | class PageBlock { |
43 | public: |
44 | PageBlock(); |
45 | PageBlock(void*, size_t, bool hasGuardPages); |
46 | |
47 | void* realBase() const { return m_realBase; } |
48 | void* base() const { return m_base; } |
49 | size_t size() const |
50 | { |
51 | return m_size - 2 * (static_cast<char *>(m_base) - static_cast<char *>(m_realBase)); |
52 | } |
53 | size_t realSize() const { return m_size; } |
54 | |
55 | operator bool() const { return !!m_realBase; } |
56 | |
57 | bool contains(void* containedBase, size_t containedSize) |
58 | { |
59 | return containedBase >= m_base |
60 | && (static_cast<char*>(containedBase) + containedSize) <= (static_cast<char*>(m_base) + m_size); |
61 | } |
62 | |
63 | private: |
64 | void* m_realBase; |
65 | void* m_base; |
66 | size_t m_size; |
67 | }; |
68 | |
69 | inline PageBlock::PageBlock() |
70 | : m_realBase(0) |
71 | , m_base(0) |
72 | , m_size(0) |
73 | { |
74 | } |
75 | |
76 | inline PageBlock::PageBlock(void* base, size_t size, bool hasGuardPages) |
77 | : m_realBase(base) |
78 | , m_base(static_cast<char*>(base) + ((base && hasGuardPages) ? pageSize() : 0)) |
79 | , m_size(size) |
80 | { |
81 | } |
82 | |
83 | } // namespace WTF |
84 | |
85 | using WTF::pageSize; |
86 | using WTF::isPageAligned; |
87 | using WTF::isPageAligned; |
88 | using WTF::isPowerOfTwo; |
89 | |
90 | #endif // PageBlock_h |
91 | |